Charles-louis gschwend



Aug 11, 1959 CHARLES-LOUIS GscHWEND 2,899,227

NOISELESS LOCK Filed Aug. 29, 1956 United States Patent O.

NOISELESS LOCK Charles-Louis Gschwend, La Chaux de Fonds, Switzerland, assgnor to Alfred Jeanrenaud, La Chaux de Fonds, Switzerland Application August 29, 1956, Serial No. 606,851

Claims priority, application Switzerland August 31, `1955 1 Claim. (Cl. 292-163) My invention has for its object a practically noiseless lock to be used on frequently opened doors such as entrance doors to houses or oices. My improved lock which reduces the noise of the locking by as much as 80% with reference to conventional locks is of the type including a cylindrical catch iitted vertically and revolubly mounted in the door frame and associated with the latch on the door. According to my invention, the latch is horizontally reciprocable against the action of a return spring and its operative end is provided next to its usual chamfered edge with a notch adapted to engage simul- .taneously two diametrically opposed generating lines of the cylindrical catch so as to prevent the latter from escaping in either direction until the latch is urged rearwardly and purposely against the action of its spring.

The accompanying drawing shows by way of example a door incorporating the invention.

Fig. l is a side-view, the door partly broken away in order to show the inside of the lock.

Fig. 2 is a cross-sectional view taken through line lI--II of Fig. 1.

Fig. 3 is a view of the latch-catch.

The lock consists of the usual parts of a classical lock, i.e. a box 11 embedded in the thickness of the door 12, said box containing the latch bolt and a latch-catch 13 fixed in the jamb-lining 14.

The latch bolt 10 is submitted to the action of a returnspring 15 o-ne of the ends of which is ixed on a pin 16. The extent of shifting of the latch is determined by an elongated slot 17 cooperating with a pin 18, whereas the edges of the opening 19 of the head piece 20, through which the head 21 of the latch comes out, are acting as guiding means together with the slot 17 and the pin 18.

The latch-catch 13 consists of an angular plate 22, screwed in a groove of the jamb-lining and of two plates 23, in which the pivots 24 of the cylinder 25 are lodged. The cylinder is made of a metal corerbar 26 covered with a sleeve of elastic material 27.

The head 21 of the latch bolt presents besides the usual chamfered edge 28 a locking notch or recess 29, limited by a cylindrical part, the diameter of which is slightly greater than that of the sleeve 27, by the backside of the chamfered part 28 and by a stud 30 formed by one of the sides of the head of the latch. The notch 29 is provided for lodging the cylinder when the door is shut and for locking the door in its closed position just before its flange 31 enters into register with the jamb-lining.

It will be noted (see Fig. 2) that the operative edge of the latch includes in sequence a bevelled or chamfered portion 28 facing the `direction of closing of the door and away from the location of the catch 25 in the closed door position, a recess or notch following immediately said bevelled portion and facing the location of the catch 25 to engage the latter in the closed door position, and a terminal portion or stud projecting slightly forward, in the direction of sliding of the latch, beyond the location of the catch when the latter has engaged said recess.

2,899,227 Patented Aug. 11, 1959 lCC As a result of this arrangement the iiange 31 does no longer play an active part in the locking of the door as this is the case with the usual locks and the repeated shocks between the door and the jamb-lining which shocks may generate noise and vibrations are thus avoided. As the only shocks, which may still generate noise, are those taking place between the latch and the cylinder, shocks which are damped by the elastic sleeve 27, the lock according to the invention meets all requirements for a noiseless working.

In order to damp the action of the cylindrical catch 21 on the latch 10 during the rearward movement of the latter, there is provided a spring 32 adapted to absorb a fraction of the kinetic energy of the door at the end of its closing movement.

In a simplied construction the cylinder 25 may be completely metallic as the noise resulting from the working of the latch is relatively unimportant in comparison with the noise which is eliminated by suppression of the registering of the door-frame with the jamb-lining.

Furthermore, the described construction is extremely simple and the wear and tear of the cylinder is very limited since it is distributed throughout the periphery of said cylinder. Further the replacement of the sleeve 27 or of the actual cylinder, when made of a single part of metal or plastic material, may be performed quickly and easily and with a minimum expense if required after a comparatively long life.

What I claim is:

The combination of a latch mechanism mounted on a door; a jamb-lining adjacent the edge of the door adapted to support a catch; said latch mechanism including a latch casing embedded in said door, a latch bolt slidable horizontally in said casing from a retracted position to a projected position wherein an end of said latch bolt extends beyond an edge of said door for engaging the catch, the said end of said latch bolt having in sequence a beveled portion, the bevel of which faces the direction of closing of said door, and a terminal portion projecting from said end at a position spaced from said beveled portion and away from the direction of closing of said door, said beveled portion and said terminal portion forming a recess which is open toward the jamblining when the door is in the closed position for engaging the catch, said terminal portion being adapted to abut the catch when said latch bolt is in the projected position, and a spring carried by and in said casing urging said latch bolt toward the projected position, whereby, upon closing of said door from an open position, the beveled portion is adapted to engage the catch causing the latch bolt to slide to the retracted position under the pressure of the catch against the resistance of said spring, and thereafter allowing said latch bolt to slide to its projected position to engage and lock the catch in its said recess and allowing said terminal portion to abut the catch; and a vertical ange extending longitudinally of said door and projecting from said edge over and beyond the said end of said latch bolt when said latch bolt is in its projected position, said vertical ange also overlying a portion of said jamb-lining with a gap between said vertical ange and said portion of said jamb-lining when said door is in the closed position.

References Cited in the tile of this patent UNITED STATES PATENTS 990,613 Voight et al. Apr. 25, 1911 1,497,044 Terrell June 10, 1924 1,497,947 Schwab June 17, 1924 1,498,897 Wittwer June 24, 1924 1,925,798 Epton et al. Sept. 5, 1933 

